A Novel Wider Range Modulation for Indirect Matrix Converter Utilizing Delta-Sigma and Space Vector

The coupling between the rectifier and inverter makes the modulation of the indirect matrix converter (IMC) relatively complicated. A novel modulation method is proposed in this letter, where a space vector modulation without a zero-voltage vector, which is only responsible for adjusting the phase of the output voltage vector, is used for the inverter, and a novel delta-sigma method (Sigma M) to modulate the input current vector phase and dc-link voltage is adopted by the rectifier. Duty cycles of the inverter are obtained by looking up the table of reference output voltages and updated at a 5-kHz carrier cycle, while switching states of the rectifier change once per cycle at a 40-kHz sampling frequency. By decoupling the rectifier and inverter, modulation of the IMC is greatly simplified. Methods that optimize the selection of rectifier switching states under various output-input voltage transfer ratios are also discussed. Simulations and experimental results are presented to validate the proposed method.